Material: Cup / Crotch: 100% Pure Silk Body Fabric: Silk-Cotton Blend (78% Organic Pima Cotton, 22% Silk) Features: Designed to improve posture, while keeping your bust secure and comfortable. Highly breathable silk and Pima cotton, hypoallergenic and soft Non-slip adjustable wide shoulder strap Smoothing coverage under arms and on back streamlines your silhouette Side support frame offers anchorage and additional support Non Wired Non-padded Only worn twice, but the cups were not big enough for me (Julie May website says these work for cups up to DD). There is some pilling on the outside lace just from friction with my shirt. This did help with posture for me. There isn't any spandex so this does not have much stretch. Size 14 / XL.